TABLE 4—
Multivariate Analysis of Annual Medicare Expenditures Among Disabled Beneficiaries With HIV: United States, 1997–2003
| Variable | Parameter Estimate (SE) | t | Prob(t) |
| Intercept | 6.43383 (0.09099) | 70.71 | <.0001 |
| Male (female) | −0.05258 (0.03001) | −1.75 | .0798 |
| Age, y (<35) | |||
| 35–44 | 0.03717 (0.03289) | 1.13 | .2585 |
| 45–54 | 0.07643 (0.03561) | 2.15 | .0318 |
| 55–64 | 0.19429 (0.04900) | 3.96 | <.0001 |
| Race/ethnicity (White) | |||
| Black | 0.40077 (0.02501) | 16.02 | <.0001 |
| Hispanic | 0.13844 (0.04562) | 3.03 | .0024 |
| Other/unknown | 0.02818 (0.06187) | 0.46 | .6488 |
| Urban county of residence (rural/unknown) | −0.05893 (0.03468) | −1.70 | .0892 |
| Region (Northeast) | |||
| Midwest | −0.27929 (0.03865) | −7.23 | <.0001 |
| South | −0.15842 (0.02920) | −5.42 | <.0001 |
| West | −0.15549 (0.03357) | −4.63 | <.0001 |
| Outlying area/unknown | −0.70765 (0.15039) | −4.71 | <.0001 |
| Partial year eligibility adjustment factora | 0.18004 (0.00654) | 27.54 | <.0001 |
| Died during year (did not die during year) | 3.00619 (0.10562) | 28.46 | <.0001 |
| Mortality rate × months of eligibility interactionb | −0.06795 (0.01399) | −4.86 | <.0001 |
| Year of expenditures (1997) | |||
| 1998 | −0.12763 (0.04714) | −2.71 | .0068 |
| 1999 | −0.15066 (0.04631) | −3.25 | .0011 |
| 2000 | −0.28499 (0.04585) | −6.22 | <.0001 |
| 2001 | −0.29990 (0.04542) | −6.60 | <.0001 |
| 2002 | −0.33083 (0.04483) | −7.38 | <.0001 |
| 2003 | −0.32346 (0.04435) | −7.29 | <.0001 |
Note. Analyses were based on log + 1 transformed annual Medicare expenditures adjusted to 1997 dollars. The reference category for each variable is in parentheses.
aAmong beneficiaries with fewer than 12 months of eligibility in a given year, the change in annual expenditures for each additional Medicare month.
bAdditional adjustment factor per added month of eligibility for beneficiaries who died in a given year.